A neural radiance field (NeRF) [1]} represents a static scene as a continuous volumetric field \(F\)  that transforms a point's position \(\mathbf {x}\)  and auxiliary variables \(\mathbf {w}\)  (e.g., view direction, latent appearance vector) to color \(\mathbf {c}\)  and density \(\sigma \) ,
\(F: (\mathbf {x}, \mathbf {w}) \mapsto (\mathbf {c}, \sigma ).\) 
